TY - JOUR
T1 - A novel low-noise measurement principle for LAPS and its application to faster measurement of pH
AU - Abu, Abu Bakar
AU - Sugihara, Hirokazu
AU - Yoshinobu, Tatsuo
AU - Iwasaki, Hiroshi
N1 - Funding Information:
The authors would like to thank the New Energy and Industrial Technology Development Organization (NEDO), the Ministry of International Trade and Industry (MITI), the Government of Japan, for supporting this work (contract no. 98S18-001).
PY - 2001/4/15
Y1 - 2001/4/15
N2 - A novel measurement principle for the light-addressable potentiometric sensor (LAPS) system is proposed in this paper. With several features like low-noise and low-background, this measurement scheme extends the application of LAPS in faster high-sensitive direct monitoring of ionic concentration and small change in the surface potential without the need of costly instruments like potentiostat, lock-in amplifier. Using two out-of-phase modulated light sources applied at two different points of the Si surface of the heterostructure, a kind of differential LAPS response is obtained. Due to the addition of the two out-of-phase photocurrents, low-frequency components associated with the photocurrents are canceled out and a low-noise and hence highly sensitive response is expected. As an application of the new principle, the pH measurement of an electrolyte solution is investigated and a new instrumentation for the direct, high-sensitive, and faster measurement of pH is proposed.
AB - A novel measurement principle for the light-addressable potentiometric sensor (LAPS) system is proposed in this paper. With several features like low-noise and low-background, this measurement scheme extends the application of LAPS in faster high-sensitive direct monitoring of ionic concentration and small change in the surface potential without the need of costly instruments like potentiostat, lock-in amplifier. Using two out-of-phase modulated light sources applied at two different points of the Si surface of the heterostructure, a kind of differential LAPS response is obtained. Due to the addition of the two out-of-phase photocurrents, low-frequency components associated with the photocurrents are canceled out and a low-noise and hence highly sensitive response is expected. As an application of the new principle, the pH measurement of an electrolyte solution is investigated and a new instrumentation for the direct, high-sensitive, and faster measurement of pH is proposed.
KW - Chemical sensor
KW - Differential measurement
KW - Light-addressable potentiometric sensor (LAPS)
KW - pH sensor
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U2 - 10.1016/S0925-4005(00)00719-X
DO - 10.1016/S0925-4005(00)00719-X
M3 - Conference article
AN - SCOPUS:0035871821
SN - 0925-4005
VL - 74
SP - 112
EP - 116
JO - Sensors and Actuators B: Chemical
JF - Sensors and Actuators B: Chemical
IS - 1-3
T2 - 5th European Conference on Optical Chemical Sensors and Biosensors
Y2 - 16 April 2000 through 19 April 2000
ER -